Indium is a chemical element. It has the chemical symbol In. It has the atomic number 49. It is a rare metal which is soft, malleable, and poor (post-transition). Indium looks like zinc. Pieces of indium can easily be joined together by pushing one piece into another. The chemistry of indium is quite like aluminium or gallium. Zinc ores are the main source of indium.
The main use of indium is in the chemical compound indium tin oxide in liquid crystal displays. It is also used in very thin layers as a lubricant. In World War II it was used to coat bearings in aircraft.